title: A comparison of two doses of omeprazole in the treatment of equine gastric ulcer syndrome: a blinded, randomised, clinical trial.
abstract: BACKGROUND
  Studies on omeprazole have reported that doses as low as 0.7 mg/kg bwt per os are potent suppressors of acid production. Yet, to date, no studies have compared treatment efficacy of different doses in clinical cases of equine gastric ulceration. Furthermore, no studies have been performed to compare the healing response of the squamous and glandular mucosa to acid suppression therapy.
  
  
  OBJECTIVE
  To compare: 1) the efficacy of 2 doses of omeprazole in the treatment of primary squamous and glandular gastric ulceration; and 2) the healing response of primary squamous and glandular gastric ulceration to acid suppression therapy.
  
  
  METHODS
  A blinded, randomised, dose-response clinical trial.
  
  
  METHODS
  Twenty Thoroughbred racehorses with grade ≥2/4 glandular ulceration were identified on gastroscopy. Seventeen horses also had grade ≥2/4 squamous ulceration. Horses were randomly assigned to one of 2 groups. Horses received either 2.0 g (high dose: 4.0 mg/kg bwt) or 0.8 g (low dose: 1.6 mg/kg bwt) of oral omeprazole per os once daily. Gastroscopy was repeated at 28-35 days.
  
  
  RESULTS
  Time and dose significantly affected grades of squamous (P<0.0001, P = 0.02) and glandular (P = 0.006 and 0.005) ulceration. Data analysis did not support our hypothesis that the lower dose would have similar effects (i.e. be noninferior) to the higher dose when considering ulcer healing and ulcer improvement. Improvement was more likely with the high dose for the squamous (P = 0.05) but not glandular (P = 0.4) mucosa. The percentage of glandular ulcers that improved was less than squamous ulcers (P = 0.02).
  
  
  CONCLUSIONS
  The results suggest that a dose-response exists for the treatment of both squamous and glandular ulcers. Improvement of glandular ulcers was not as complete as observed with squamous ulcers and current equine gastric ulcer syndrome treatment recommendations may not be appropriate for glandular disease.
authors.affiliation: BW Sykes Consultancy, Upper Orara, New South Wales, Australia.
authors.forename: B W
authors.initials: BW
authors.lastname: Sykes
authors.forename: K M
authors.initials: KM
authors.lastname: Sykes
authors.forename: G D
authors.initials: GD
authors.lastname: Hallowell
mesh_terms: D000818:Animals; D000897:Anti-Ulcer Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006734:Horse Diseases / Q000188:drug therapy*; D006736:Horses; D008297:Male; D009853:Omeprazole / Q000008:administration & dosage / Q000627:therapeutic use*; D013276:Stomach Ulcer / Q000188:drug therapy / Q000662:veterinary*
chemical_list: D000897:Anti-Ulcer Agents; D009853:Omeprazole
keywords: gastric; horse; proton-pump inhibitor; stomach; ulcer